Britain considered taking punitive action against the London headquarters of Iran's English-language state broadcaster earlier this year after Iran jammed the signals of the BBC's Persian TV service (PTV), according to a US state department document released by WikiLeaks.

Press TV is an arm of the Iranian state broadcaster, IRIB. Its main foreign bureau is in north-west London. Presenters include the former Labour and Respect MP George Galloway, whose programme was recently criticised by Ofcom for breaching impartiality rules, and the journalist Yvonne Ridley.

No steps were taken at the time because of legal difficulties, but a British official said a case could be made in future if new sanctions were imposed on Iran, the secret US cable reported. New sanctions were imposed by both the UN security council and the EU in the summer, but no action has been taken against the broadcaster.

The action was considered after repeated electronic jamming of the BBC's PTV and the Voice of America's Persian service. It was blamed on the Iranian government.

Eutelsat, the owner of the Hotbird satellite, decided after months of jamming to drop PTV from the satellite because of complaints from other commercial broadcasters that their programmes were being affected as well. Eutelsat gave PTV a slot on another satellite that did not carry many of the most popular channels and had limited reach.

Britain urged the US to join it and France in lobbying the International Telecommunication Union (ITU), which regulates satellite transmissions, against the Iranian government, while also acknowledging that it had no enforcement authority.

It was therefore "looking at other ways to address the issue … and exploring ways to limit the operations of the IRIB's Press TV service". The difficulty, the cable continued, was that "UK law sets a very high standard for denying licences to broadcasters. Licences can only be denied in cases where national security is threatened, or if granting a licence would be contrary to Britain's obligations under international law. Currently neither of these standards can be met with respect to Press TV, but if further sanctions are imposed on Iran in the coming months a case may be able to be made on the second criterion".

BBC PTV was launched in January 2009 and generated Iranian government fury. Sporadic interference began after the disputed presidential elections that June and intensified when there was a new spate of demonstrations in late December. Tehran has repeatedly attacked PTV as an arm of the British government, accusing it of seeking to foment a "velvet revolution".

Iran expelled the BBC's Iran correspondent during the 2009 unrest, but in an apparent softening of its position recently agreed in principle with the BBC to let a new correspondent visit Tehran regularly on a trial basis.